1. Field of the Invention
This invention relates to latch assemblies for releasably maintaining movable closure elements in a desired position relative to a support therefor.
2. Background Art
Myriad designs for latch assemblies for maintaining movable closure elements in a desired position relative to a support upon which the movable closure element is mounted have been devised over the years. Different demands are placed upon these mechanisms depending upon their particular environment. However, designers of these latch assemblies universally consider and balance the following factors in their designs: 1) reliability; 2) holding capacity; 3) convenience of operation; 4) ease of manufacture; 5) ease of assembly; 6) versatility; and 7) cost. Certain of the above factors are competing in the design process and, generally, particular applications will dictate where compromises must be made. Ideally, one would optimize each of these design areas.
The agricultural and construction industries are ones in which rather severe demands are placed upon latch assemblies. Severe stresses are commonly placed on closure elements on cabs of tractors and the like. At the same time, convenience of actuation is a prime consideration, as when a hasty exit must be made from such a vehicle. This has lead to the use of squeeze-actuated assemblies of the type shown in U.S. Pat. No. 6,419,284. The squeeze actuator is integrated into a bar which facilitates manipulation of the closure element as well as accessibility to the lever that is squeezed while gripping the bar to release the latch assembly to permit opening of the closure element. However, the latch assembly designs, of the type shown in U.S. Pat. No. 6,419,284, have tended towards the complicated. For example, the design shown in U.S. Pat. No. 6,419,284 uses two separate, indirect mechanisms for moving a catch element through separate internal and external actuating assemblies on the closure element. This indirect actuation requires intermediate parts which may complicate the manufacturing process and increase associated costs. Indirect mechanisms, by their nature, introduce additional parts movement that could account for a field failure.
Typically, latch assemblies are designed to be operated by interior and exterior actuating assemblies, each with a specific design. There currently exist a number of different types of actuating assemblies, among which are actuating assemblies utilizing a pivotable trip lever that operates in conjunction with an elongate handle to be squeeze operated, actuating assemblies having a pull-type, graspable handle, and actuating assemblies utilizing a depressible element, i.e. a push button system. Some of these latch assemblies have mechanisms which cooperate with strike elements in the same manner. The difference between these latch assemblies may thus reside only in the configuration of the actuating assemblies. These various types of latch assemblies are conventionally sold with a single, specific combination of interior and exterior actuating assemblies.
Accordingly, purveyors of this type of equipment are required to anticipate demands for a particular overall latch assembly configuration. Unless the latch assemblies are built to order, purveyors must make an educated estimate as to demands for a particular type of latch assembly, at the risk of carrying excess inventory of one style and having a shortage of another.
Additionally, offering a line of latch assemblies with different combinations of actuating assemblies may add appreciably to the cost of such systems. An increased number of assembly steps and/or lines may be required to offer latch systems with all available combinations of actuating assemblies.
The industry is constantly seeking out latch assemblies that are improved in one or more of the areas noted above.